# include<stdio.h>
# include<stdlib.h>

#define MY_ENY "myval"

int main()
{
    // 通过getenv这个系统调用来了解本地环境变量
    char* myenv = getenv(MY_ENY);
    if(myenv == NULL)
    {
        printf("%s, not found\n", MY_ENY);
    }
    else
    {
        printf("MY_ENY:%s\n", MY_ENY);
    }


    return 0;
}
